marshmallow-sqlalchemy¶
Release v0.21.0 (Changelog)
SQLAlchemy integration with the marshmallow (de)serialization library.
Declare your models¶
import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session, sessionmaker, relationship, backref
engine = sa.create_engine("sqlite:///:memory:")
session = scoped_session(sessionmaker(bind=engine))
Base = declarative_base()
class Author(Base):
__tablename__ = "authors"
id = sa.Column(sa.Integer, primary_key=True)
name = sa.Column(sa.String)
def __repr__(self):
return "<Author(name={self.name!r})>".format(self=self)
class Book(Base):
__tablename__ = "books"
id = sa.Column(sa.Integer, primary_key=True)
title = sa.Column(sa.String)
author_id = sa.Column(sa.Integer, sa.ForeignKey("authors.id"))
author = relationship("Author", backref=backref("books"))
Base.metadata.create_all(engine)
Generate marshmallow schemas¶
from marshmallow_sqlalchemy import ModelSchema
class AuthorSchema(ModelSchema):
class Meta:
model = Author
class BookSchema(ModelSchema):
class Meta:
model = Book
# optionally attach a Session
# to use for deserialization
sqla_session = session
author_schema = AuthorSchema()
Make sure to declare Models
before instantiating Schemas
. Otherwise sqlalchemy.orm.configure_mappers() will run too soon and fail.
(De)serialize your data¶
author = Author(name="Chuck Paluhniuk")
author_schema = AuthorSchema()
book = Book(title="Fight Club", author=author)
session.add(author)
session.add(book)
session.commit()
dump_data = author_schema.dump(author)
print(dump_data)
# {'books': [123], 'id': 321, 'name': 'Chuck Paluhniuk'}
load_data = author_schema.load(dump_data, session=session)
print(load_data)
# <Author(name='Chuck Paluhniuk')>
Get it now¶
pip install -U marshmallow-sqlalchemy
Requires Python >= 3.6, marshmallow >= 2.15.2, and SQLAlchemy >= 1.2.0.